(CBS News) Maureen O'Connor was a beloved former mayor of San Diego. But O'Connor's life took a stunning turn after it was revealed she gambled away a fortune.

Prosecutors believe she won and lost more than $1 billion, playing video poker, raiding a charity foundation of $2 million to feed her gambling habit.

O'Connor sat down with CBS News' Bill Whitaker to explain what she thinks led to the addiction that has left her bankrupt.

Asked what's the worst of the situation for her, O'Connor said, "I couldn't do it in private. Very public. If I had my wish, I wished it would be gamblers anonymous, not, 'here's Maureen's story.'"

O'Connor said her story plays out in two acts: "Maureen 1" was mayor of San Diego. Her second act is unfolding in national headlines: a tawdry tale of gambling and lost fortunes. The widow of Robert Peterson, the founder of the West Coast fast-food chain, Jack-in-the-Box, she inherited as much as $50 million, say federal prosecutors.

"I used some of that fortune to help people. And then, some of that fortune, when I started to become 'Maureen 2,' went into an addiction of gambling. ... I lost a fortune. And for that I'm sorry," O'Connor said.

Her game of choice: video poker. She was such a big spender, casinos in San Diego and Las Vegas would lavish her with gifts to keep her coming. She would have come anyway. "It was like electronic heroin," O'Connor said. "You know, the more you did, the more you needed and the more it wasn't satisfied."

She told CBS News she could lose more than $100,000 in a day.

Increasingly desperate, she started to sell off properties to raise millions more -- including a house in an exclusive beach community in La Jolla, right by neighbor, Mitt Romney.

Phillip Halpern, federal prosecutor for the U.S. Department of Justice, said, "And only after all that was done, did she then go and raid a private foundation of over $2 million."

She took the money from her husband's charity. She called it a loan to be paid back. Halpern called it a money laundering and says she won and lost a staggering amount. He said, "We're talking about billions with a 'B.' It's not against the law to bankrupt yourself. The violation was that she raided that charity of $2 million."

For O'Connor -- now penniless -- it's a public humiliation.

O'Connor said during a tearful press conference recently, "I never meant to hurt the city that I loved."

San Diego once loved her. She was the first woman mayor. From 1986 to 1992, she brought in light rail, a convention center, and helped transform San Diego from a sleepy Navy town into the country's eighth largest city.

O'Connor said of the time, "I was interested in doing everything I could to make the city a better city."

As mayor she was always in control. Her gambling was out of control.

"I thought I could beat that machine," she said. "And when it got worse, I didn't know I had the silent grenade in my head that could go off at any time."

The "silent grenade" was a golf ball-sized tumor doctors removed from her brain. They discovered it two years ago when she started hallucinating. She says she believes the slow-growing tumor contributed to her gambling addiction. "It's not an excuse for my gambling, but I think that was, yes, a part of it. You lose your sense of control," she said.

The tumor could have affected her behavior, says her neuropsychologist, Dr. Barbara Shrock. She said, "In about 20 percent of cases in tumors, psychiatric personality or behavioral changes often time are the first symptom of the tumor."

But Halpern is skeptical, saying "she began her gambling run in 2001 -- a decade earlier. It would have to be a pretty slow-growing tumor."

Halpern said the Justice Department will drop the charges if O'Connor repays the charity and gets help for gambling addiction.

O'Connor said, "After the tumor was taken out and I started healing, I have no desire to gamble."

She does desire her city's forgiveness. O'Connor said, "I would hope they would remember 'Maureen 1,' and 'Maureen 2' -- I hope that they would understand."